Electrophotographic photoreceptors, electrophotographic photoreceptor cartridge, and image-forming apparatus

1. An electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer formed thereover, wherein the photosensitive layer contains at least a polyarylate resin having a repeating structure represented by formula [1] and a compound represented by formula [6]:

wherein in formula [1], Ar 1 to Ar 4 each independently represent an arylene group which may have a substituent; X is a single bond, an oxygen atom, a sulfur atom, a group represented by formula [2], or a group represented by formula [3]; R 1 and R 2 in formula [2] each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R 1 and R 2 may be bonded to each other to form a ring; R 3 in formula [3] represents an alkylene group, an arylene group, or a group represented by formula [4]; R 4 and R 5 in formula [4] each independently represent an alkylene group; and Ar 5 represents an arylene group; k represents an integer of 1; and Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by formula [5], wherein R 6 and R 7 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, and R 6 and R 7 may be bonded to each other to form a ring:

wherein in formula [6], Ar 6 to Ar 9 may be the same or different and each represent an aryl group which may have a substituent.

2. The electrophotographic photoreceptor according to claim 1 , wherein X in formula [1] is an oxygen atom, a sulfur atom, the group represented by formula [2], or the group represented by formula [3].

3. The electrophotographic photoreceptor according to claim 1 , wherein the photosensitive layer comprises a charge-generating layer and a charge-transporting layer, the charge-generating layer and the charge-transporting layer having been laminated in this order over the conductive substrate.

4. An electrophotographic cartridge comprising:

the electrophotographic photoreceptor according to claim 1 ; and

at least one member selected from a charging device which charges the electrophotographic photoreceptor, an imagewise-exposure device which imagewise exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image, a developing device which develops the electrostatic latent image with a toner, a transfer device which transfers the toner to a receiving object, a fixing device which fixes the toner transferred to the receiving object, and a cleaner which recovers the toner adherent to the electrophotographic photoreceptor.

5. An image-forming apparatus comprising:

the electrophotographic photoreceptor according to claim 1 ;

a charging device which charges the electrophotographic photoreceptor;

an exposure device which exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image;

a developing device which develops the electrostatic latent image with a toner; and

a transfer device which transfers the toner to a receiving object.

6. An electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer formed thereover, wherein the photosensitive layer contains at least one compound represented by formula [7′]:

wherein in formula [7′], Ar 10′ , Ar 11′ , and Ar 12 to Ar 15 may be the same or different and each represent an aryl group which may have a substituent; n represents an integer of 2 or larger; Z represents a monovalent organic residue; and m represents an integer of 0 to 4, provided that at least one of Ar 10′ and Ar 11′ is an aryl group having a substituent.

7. The electrophotographic photoreceptor according to claim 6 , wherein m is 0.

8. The electrophotographic photoreceptor according to claim 6 , wherein the photosensitive layer comprises a charge-generating layer and a charge-transporting layer, the charge-generating layer and the charge-transporting layer having been laminated in this order over the conductive substrate.

9. An electrophotographic cartridge comprising:

the electrophotographic photoreceptor according to claim 6 ; and

at least one member selected from a charging device which charges the electrophotographic photoreceptor, an imagewise-exposure device which imagewise exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image, a developing device which develops the electrostatic latent image with a toner, a transfer device which transfers the toner to a receiving object, a fixing device which fixes the toner transferred to the receiving object, and a cleaner which recovers the toner adherent to the electrophotographic photoreceptor.

10. An image-forming apparatus comprising:

the electrophotographic photoreceptor according to claim 6 ;

a charging device which charges the electrophotographic photoreceptor;

an exposure device which exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image;

a developing device which develops the electrostatic latent image with a toner; and

a transfer device which transfers the toner to a receiving object.

11. An electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer formed thereover, wherein the photosensitive layer contains at least a polyarylate resin having a repeating structure represented by formula [1] and a compound represented by formula [7]:

wherein in formula [1], Ar 1 to Ar 4 each independently represent an arylene group which may have a substituent; X is a single bond, an oxygen atom, a sulfur atom, a group represented by formula [2], or a group represented by formula [3]; R 1 and R 2 in formula [2] each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R 1 and R 2 may be bonded to each other to form a ring; R 3 in formula [3] represents an alkylene group, an arylene group, or a group represented by formula [4]; R 4 and R 5 in formula [4] each independently represent an alkylene group; and Ar 5 represents an arylene group; k represents an integer of 0 to 5, provided that when k=0, either Ar 3 or Ar 4 is an arylene group having a substituent; and Y is a single bond, an oxygen atom, a sulfur atom, or a group represented by formula [5], wherein R 6 and R 7 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group, and R 6 and R 7 may be bonded to each other to form a ring:

wherein in formula [7], Ar 10 to Ar 15 may be the same or different and each represent an aryl group which may have a substituent; n represents an integer of 2 or larger; Z represents a monovalent organic residue; and m represents an integer of 0 to 4.

12. The electrophotographic photoreceptor according to claim 11 , wherein the photosensitive layer comprises a charge-generating layer and a charge-transporting layer, the charge-generating layer and the charge-transporting layer having been laminated in this order over the conductive substrate.

13. An electrophotographic cartridge comprising:

the electrophotographic photoreceptor according to claim 11 ; and

at least one member selected from a charging device which charges the electrophotographic photoreceptor, an imagewise-exposure device which imagewise exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image, a developing device which develops the electrostatic latent image with a toner, a transfer device which transfers the toner to a receiving object, a fixing device which fixes the toner transferred to the receiving object, and a cleaner which recovers the toner adherent to the electrophotographic photoreceptor.

14. An image-forming apparatus comprising:

the electrophotographic photoreceptor according to claim 11 ;

a charging device which charges the electrophotographic photoreceptor;

an exposure device which exposes the charged electrophotographic photoreceptor to light to form an electrostatic latent image;

a developing device which develops the electrostatic latent image with a toner; and

a transfer device which transfers the toner to a receiving object.